1. Field of the Invention
The invention concerns methods for intraoperative generation of an updated volume data set of a patient.
2. Description of the Prior Art
In the course of a medical procedure on a patient, in particular a minimally invasive procedure, it is frequently necessary to monitor position changes of biological tissue in the patient by means of diagnostic x-ray imaging. Such a requirement exists, for example, in the case of complicated fractures, in particular multiple fractures with a number of small bone fragments with complex morphology, which in the osteosynthesis must be aligned and set relative to one another. Conventionally, the repositioning of the bone fragments and their subsequent setting ensue using individual 2D x-ray projections, and the surgeon during the minimally invasive procedure must mentally reconstruct the three-dimensional anatomical situation in reality from the 2D x-ray projections acquired at different viewing angles. This mental 3D reconstruction of the real three-dimensional anatomical situation from a number of 2D x-ray projections acquired intraoperatively requires a great deal of experience, imagination, and concentration on the part of the surgeon.
It also is possible to generate, with a C-arm x-ray device, a volume data set containing image information about the bone fragments at definite points in time after the positioning of the patient. To product the volume data set a series of 2D x-ray projections is acquired at various projection angles. The surgeon would prefer to undertake the osteosynthesis using such volume data generated intraoperatively, from which 2D or 3D images can be generated. This is not currently possible because the 3D image data do not represent an image that is sufficiently current, since a frequent or even continuous complete intraoperative update of the 3D image data during the continuous repositioning of the bone fragments is not possible, both due to time consideration and due to radiation shielding consideration.